The Value Of Ct Perfusion Imaging In The Evaluation Of Delayed Cerebral Ischemia In Patients With Aneurysmal Subarachnoid Hemorrhage

Objective: The purpose of this study was to study the value of CT perfusion imaging in the evaluation of delayed cerebral ischemia(DCI)in patients with aneurysm subarachnoid hemorrhage(a SAH).Methods: This study was a retrospective cohort study.A total of 67 patients with aneurysm subarachnoid hemorrhage(a SAH)hospitalized in Hangzhou normal University affiliated Hospital from January 1,2017 to March 31,2022 were selected.Patients who completed CT perfusion examination within 24 h after onset were selected to detect the changes of early cerebral microcirculation by CT perfusion imaging.The patients were divided into two groups according to their clinical manifestations,CT imaging findings and prognosis: DCI group.Non-DCI group.CT perfusion imaging indexes and general clinical data of patients including age,sex,hypertension,diabetes mellitus,admission related scores such as Hunt-Hess grade and modified Fisher grade on delayed cerebral ischemia were analyzed,and the prognostic risk factors were analyzed.Results: 1.There was no significant difference in sex,age,history of hypertension,history of diabetes,hyponatremia,hyperlipidemia,hypoalbuminemia,cerebral vasospasm and location of responsible aneurysm between DCI group and non-DCI group,but there were significant differences in modified Fisher grade,Hunt-Hess grade,cerebral vasospasm,intraventricular hemorrhage and pulmonary infection.2.The mean cerebral blood flow(CBF)and cerebral blood volume(CBV)in the DCI group were significantly lower than those in the non-DCI group,and the average transit time(MTT)and the peak time(TTP)were longer in the MCBF group than those in the non-CBP group.3.For the prediction of delayed cerebral ischemia DCI by CT perfusion imaging,(1)the area under the receiver working characteristic curve of cerebral blood volume CBV is 0.759,the best critical point is 3.25ml/100 mg,the sensitivity is 77.6%,the specificity is 50%;(2)the area under the CBF curve of cerebral blood flow is 0.812,the best critical point is 42.7ml/100mg/min,the sensitivity is 71.4%,the specificity is 72.8%.(3)the area under the average transit time MTT curve is 0.753,the best critical point is 5.35 s,the sensitivity is 83.3%,and the specificity is 57.1%;(4)the area under the TTP curve of peak time is 0.685,the best critical point is 10.25 s,the sensitivity is 72.2%,and the specificity is 65.3%.4.Analysis of prognosis: cerebral vasospasm,delayed cerebral ischemia,pulmonary infection and hyponatremia,modified Fisher grade and Hunt-Hess grade were the risk factors of poor prognosis.The proportion of cerebral vasospasm,delayed cerebral ischemia,pulmonary infection and hyponatremia in the poor prognosis group was higher than that in the good prognosis group,and the proportion of modified Fisher grade 3-4 and Hunt-Hess grade 4-5 was higher.Conclusion: CT perfusion imaging shows that the perfusion characteristics of brain tissue are significantly related to the occurrence of delayed cerebral ischemia in patients with aneurysm subarachnoid hemorrhage(a SAH).Delayed cerebral ischemia is one of the risk factors for poor prognosis in patients with a SAH.CT perfusion imaging has a certain clinical value for early identification of undetermined ischemia,formulation of treatment plan and prognosis evaluation.